This project is directed toward utilizing computerized tomography and ultrasound to improve radiation therapy treatment planning. A whole-body X-ray scanner and a PDP-11/70 computer have been installed. Multiple CT images can be simultaneously displayed on one video monitor as a function of either image spatial sequence or time. Automatic contouring with quick edit option has been implemented. Contour area, mean density, and density histogram can be automatically produced on monitor. Distances between points can be calculated in real dimensions to provide accurate definition of tumor depths. Mathematical models of X-ray beams have been entered and adjusted so that patient treatments can be accurately simulated by the computer prior to exposing patients to radiation. Routine treatment planning has been initiated.